Ellipsograph



Patented Sept. 6, 1932 UNETED stars NATHAN w. OLBYRNE,- or, BALnwin, KANSAS ELLIPSOGBAPH Y Applicationnled Januar 4, 1932. Serial No; 584,857.

This invention relates to instruments for producing curved lines and particularly 'el- 'lipses, and the primary object of theinvention is to provide a structure known as an ellipsograph which may be used in scrib ng ellipses on any sheet of material, OIiWl llCh may be used for cutting mats, etching or cutting glass, or simply to apply a seriesof parallel ellipses upon a flat surface.

One of the primary objects of the instant invention is the contemplation of an ellipsograph that is extremely compact; comprlses -a minimum number of parts, yet performs 1 the functions desired in a manner permitting lines or ellipses produced. Another object of the present invention is the provision of an ellipsograph that has a combination of parts to cause an action that is easily applied to any problem of describing an ellipse and that may be used commercially without encounterlng the custom- ,ary requirements of setting and intrlcate adjustment. 1Further and important objects of the 1nvention will appear during the course of the following specification, referring to theaccompanying drawing, wherein a preferred embodiment of the conception has been illustrated and wherein: I a

Figure 1 is a top plan view of an ellipsograph in position for use andembodying this invention.

.35 the ellipsograph as it is illustrated in Fig.1.

Fig. 8 is aside elevation of the same,,and,

designate like parts throughout the several views of the drawing and-the numeral 6 indicates a base having an annular upwardly extending flange 8 and a series of diametrically opposed indicator pointers 1O formed integrally therewith. l i

These pointers 10 are used to properly position the ellipsograph when bringing the same into use and, if desired, a number-of spurs 12 may be associated with base 6to preclude mal- V flexibility as to size and position of the curved- V i member rotatably attaches pinion 18 to one end of crank lever 22 while pintle 2 pivotally Fig. 2 is a vertical, central section through adjustment, after once locating theinstrument. i To carry out one of the salient features of the invention, an internal gea'r'lt is mounted upon base 6 by engagementwith flange 8, as .6}

illustrated in Fig. 2. Screws or analogous means 16 mayaugment this structure to pre clude relative movement between base and internal gear 6 and 14 respectively. Apinion 18 is assembled with its teeth in mesh with -99 the teeth o'f'internal gear 14 and is rotatably supported by member 20 to permit its independent rotation as it is carried around the axis of internal gearl i by crank lever 22. I

Reference to Fig. 2 readily discloses that 8? aflixes'the other end of crank lever 22 to base 6 at the axis of internal'gear 14. Members 20 and 24. may be of any suitable form, but in the 1'9 instance shown, have been made to be shouldered and appropriately ailixed in position so that there is no binding or false movements to preclude free action-byithe ellipsograph when it is being used. A bearing such as the (6 ball 26 may be provided at'the free end of crank lever 22 to assist in this aforementioned desirable free actiomand means is likewise provided to steady the instrument as the by one hand of the operator. In the instance shown, neck 28 is bifurcated at its lower end to straddle member 20 and to presentoutturned feet 32, through which may pass the fastening means 84; serving, to assemble neck 28 and pinion 18.' j Knob 30 is mounted for free rotation up'on the upper end of neck 28, and if found. appropriate, ball bearings 36 may be utilized atthis point to lend free movement. Aremovable screw '38 may be used tomaintain knob 9 position. v V V In the drawing a marker 10 has been illustrated to be an ordinary pencil, but it is understood thatlin place of such a marker, a cutter knife or any other instrument might befused [I] lvtanifestlany =be..carried by neck28 and whencertain of without alterin the principal action of the ellipsograph. ll Iarker 40 is attached to neck 28 through the intermediacy of an arm 42. A transverse opening 44 is formed through neck 28 to receive arm 42 and a clamping screw46 is set in position to intersect opening 44, whereby arm 42 may be clamped when the desired ad ustment is reached.

Reference to Fig. 1 teaches that a series of graduated markings 47 may;- beinscribed upon the top of arm 42 to facilitate setting of the instrument. Arm 42 is jointed toallow vertical movement of marker 40 as the same is traveling through its elliptical path. This construction compensates for any irregularity which may be present on the surface of board or other material 48.upon which is beinginscribed the ellipse illustrated by line 50 in Fig. 1. A cross pin 52 at the joint in arm 42 permits such movement and a set screw 54 is present to allow adjustment, replacement or substitution of marker40.

' The operation of the ellipsograph just described is obvious and itis but necessaryto set down the fact that neck, arm and marker 28', 42 and'4O respectivelymove about the axis of pinion 18 when the pinion is independently rotated'by grasping the upper end of'marker 40.. When pinion 1 8. is thus rotated about member 20, its engagement with internal gear 141 will immediately set upa driving action which 7 carries the entire assemb y just enumerated, pinion 18, and crank lever 22 aboutpintle 24 in a direction which is opposite-to the direction of travel of marker 40. The arrows in Fig. 1 illustrate the above statement. V i

The pitch diameterof pinion 18 is just one-half the pitch diameter of internal gear 14 and one complete revolution on the part of pinion 1 8 will carry thesame to a point.

diametrically opposite to the position illustrated in Fig; '1; Ingtraveling to this point,

'marker 40 will be drawn progressivelycloser to the circumference of internal gear 14. and, it is obvious, it will be closest to-internal gear 14 when pinion 18 has traveled onequarter of the way around internal gear 14. Moving marker 40 once around internal gear 1.4 wi1l cause pinion 18' to pass throughits path of travel twice and thus an ellipse similar to that outlined by line 50 Willbe inscribed. 1

part of. arm 42 allows an ellipseof any size to bedrawn; the limitation of such an ellipse as to its minor diameter being allowed by ythe;distancebetween diametrically opposed pointers 10. j number of arms 42 jnfay said arms are desired'to be left inoperative,

by Letters Patent is:

and marker 40 overhang the rethe outer portion of arm 42 .may be swung about pin 52 so that marker 40 is not in position upon board 48. 7 Unlike so many instruments of this character, it is possible'to draw parallel ellipses and thus make elliptical borders or other decorative concentric or parallel ellipses Wherever desired. The possibilities and flexibility of an ellipsograph embodying the features of this invention are unlimited. ,AsaneXample, when it is desired to produce an ellipse with a major axis at right angles to the major axis of a previously described ellipse, it is but necessary to lift basetiand set the pair of pointers 10 line'when the first ellipse was formed."

Having thus described the invention, what is claimed as new and desired to be secured .1. In an ellipsograph, an internaligear; a pinion in mesh with said gear; a crank lever interconnecting said internalgear and pinion; and a marker carried by said pinion.

2. In an ellipsograph, an internal gear; a

pinion in mesh with said gear; a crank lever having one end pivotally attached at the axis of said internal gear; and a marker carried by the pinion, said pinion being rotatably supported by the free end of said crank-lever.

3. In an'ellipsograph, an internal gear;'a crank lever having one end pivotally attached at the axis of said internal gear; a pinion inmesh with said internal gear and rota-tably supported by the other-end of said crank lever; a neck rigid with said pinion; and an arm adj ustablycarried'by the neck. 7

4.]I'n an elllpsograph, an internal gear; a

pinion in mesh with said gear; means mounting said pinion for independent rotation about its own-axis and for travel'in a conaround the internal gear by said arm. I

6. In. an ellipsograph, aninternalgear; a. pinion inxmesh with said gear; means mountingv said pinion for independent rotation about itsown axis and for travel in a con centric path around the axis of said internal gear; a'neckrigid with thepinion; anarm slidably mounted on-the neck; and a markercarried by the arm.

.7.In an ellipsograph, a anlinternal gear on.thebase;. a crank leverpivotallyat tached atitsone end tosaid base, at the axis -ment of said marker as the same is. guided H of said internalgear; :a pinion inmesh with the internal gear and rotatably supported at the other end of said crank lever; and a marker overhanging said base and internal gear.

8. In an elhpsograph, a base; an internal gear onthe base; a crank lever pivotally attached at its one end to said base, at the axis of said internal gear; a pinion in mesh with the internal gear and rotatably supported at the other end of said crank lever; an upstanding neck rigid with said pinion; a knob rotatably mounted on said neck; and a marker adjustably carried by said neck to overhang said base and internal gear.

In testimony whereof, I hereunto aflix my signature.

NATHAN W. OBYRNE. 

